1. Field of the Invention
The invention relates to a bearing arrangement; and more specifically to an arrangement having an inner sleeve with a contact portion.
2. Description of Related Art
Elastic bearings in motor vehicle wheel suspensions connect parts movable relative to one another. Such elastic bearings may include rubber/metal composite bearings. A rubber/metal bushing has a metallic inner sleeve surrounded concentrically by a rubber-elastic element and normally includes a metallic outer sleeve. The inner sleeve is connected to a suspension part while the outer sleeve, or the rubber-elastic element, connects to a different suspension part. The elasticity of the rubber-elastic element allows movement between the two suspension parts to a limited extent. Defining an axial direction by the profile of the inner sleeve, axial, radial, tangential and unchanged movements are thus conceivable. The bearing acting, a limited extent, in a similar manner to a ball joint. Besides the fact that various degrees of freedom are created by the elasticity, the rubber-elastic element also prevents the transmission of vibrations that are undesirable in terms of NVH aspects.
One example of a use for such bearings is a transverse control arm, where a connection to a wheel carrier or a vehicle structure is often carried out via rubber/metal bearings. In one example of such a connection, the bushing is pressed, with the outer sleeve, into a recess in the control arm, while a vehicle-side axle extends through the inner sleeve. The axle can be formed by a bolt, screw, threaded member or other fastening mechanism extending through openings in portions lying axially opposite one another of the vehicle structure. The head of the bolt or screw bears against one portion, while a nut screwed onto the threads bears against the other portion. The inner sleeve positioned between the portions is compressed by the axial tensioning force generated by the combination of the bolt and nut, which generates a clamp force against the inner sleeve.
The dimensions of the inner sleeve and the bolt are matched to one another so at least some small radial spacing exists facilitating insertion of the bolt into the inner sleeve during assembly. Because of the radial spacing, there is no positive fit or frictional connection between the bolt and the inner sleeve. Transverse forces acting on the side of the control arm are transmitted from the rubber-elastic element to the inner sleeve and in a frictionally engaged manner directly to the respective portions of the vehicle structure, i.e., the flow of force does not run through the bolt, rather only in the frictional engagement at the end faces of the inner sleeve. Bearing forces acting transverse to the axial direction are exclusively transmitted via a contact surface between the inner sleeve and the respective portion of the vehicle structure which acts as a shear surface. A contact surface between the bolt and the vehicle structure or an intermediate element such as a washer does not contribute to the transmission of force.